what will switching to the 3" blower drive pulley do for you blown?

If he's doing what I think he is (reducing the size of the pulley on the blower) it will spin faster and create more boost.

go to my garage and take a look at my dyno sheet, you will see where i start to pull with the 206 cams, these pulls are without the nitrous, all motor and tuning

nice very nice....whats all done to your truck?